Embodiments of the present invention generally relate to a joining element for use with a conduit and a method of making a connection with the joining element. More specifically, embodiments of the present invention relate to a connector for joining a tube on an analytical instrument and a method for making such a connection.
An analytical instrument may be a complex machine which performs a number of predetermined tasks. In order to perform these predetermined tasks, the analytical instrument may have structures dedicated to performing elements of those tasks. For instance, a biological sample analyzer may comprise a fluid system and a detection system. The fluid system may provide fluids, such as reagents and the like, to the sample. The sample/reagent mixture may be incubated. After incubation, the sample/reagent mixture may be read by the detection system thereby providing an operator with desired data.
In order for the analytical instrument to perform according to expectations, it is desirable that each element of the instrument function optimally. For example, it is desirable that every element of the detection system and the fluid system operate in an intended fashion. If an element of either the detection or fluid system were not to operate as expected, the entire instrument may not function according to specifications. This might result in inaccurate data being supplied to the instrument operator.
Focusing on the fluid system, it may comprise a series of conduits or tubes joined to ports in other structures in the instrument by a connector. Because the tubes may convey fluid, such as reagents and the like, from one part of the instrument, such as a stock bottle, to other parts of the instrument, such as a pump, a dispense head and the like, it is beneficial that no fluid leaks from any of the connections. Some reagents may be expensive, thereby further emphasizing the need to have no leaks.
The connections between the tubes and the other parts of the instrument may be made by connectors which compress the tubes or other structures in an effort to form a substantially fluid-tight connection. Also, the connection may be made by a threaded coupling of the connector and the port of the instrument.
Because of their constructions, some connectors may not perform according to expectations. Connectors that are produced in large quantities may exhibit variations from one connector to another. These variations may compromise the integrity of the connection made between the tube and the instrument, thereby possibly resulting in a fluid leak.
Connectors that utilize a threaded coupling may be sensitive to installation forces, such as a torque applied to the connector to engage threads. In some cases, an installer may apply too much torque, i.e. tighten the connector too much, in an effort to prevent a fluid leak. Over-tightening the connector may cause the tube to collapse to a certain extent. This can inhibit fluid flow through the instrument. On the other hand, if the connectors are not sufficiently tightened, they may leak. Because the connector may not provide the installer with an indication of a proper connection (appropriate tightness), the installer may not know if he has tightened the connector too little or too much.
In some cases, the connectors may loosen over time. In these cases, the connectors may have to be re-tightened periodically. But, an analytical instrument may be quite complex. The connectors may be difficult to reach and therefore difficult to re-tighten. Some connectors may require a tool for installation and re-tightening which may further complicate maintenance of the connection and the instrument.
During operation of an analytical instrument, various forces may be applied to a tube. These forces may try to pull the tube out of a connector. To reduce the probability that a tube will be pulled out of a connector, the connector may be provided with a blade-like member. This blade-like member is intended to cut into the tube just enough to resist the tube being pulled out of the connector. However, in some connectors, the distance of the cut into the tube is dependent upon how much the connector is tightened into the instrument. Therefore, if the installer over-tightens the connector, the blade-like member may cut too far into the tube, thereby possibly resulting in a leak. Alternatively, if the connector were insufficiently tightened, then the tube may pull away from the connector and the instrument port, also possibly causing a fluid leak.
Additionally, the construction of some connectors may not allow them to be reused. Removal of an connector from an instrument may damage the connector beyond repair. Also, the connector may damage the tube to such an extent that the tube as well as the connector must be replaced. Also, once the connector is disassembled, the individual parts comprising the connector may be lost.